Heat dissipation plate and method for manufacturing the same

ABSTRACT

A heat dissipation device includes a first plate having a first plurality of angled grooves arranged in a first direction, and a second plate having a second plurality of angled grooves arranged in the first direction. The second plate is coupled to the first plate, at least portions of the first plurality of angled grooves and the second plurality of angled grooves are connected to each other such that the first plurality of angled grooves and the second plurality of angled grooves define a fluid channel of the heat dissipation device, and the fluid channel includes coolant. The heat dissipation device also includes at least one capillary structure. At least a portion of the fluid channel is covered by the at least one capillary structure.

CROSS-REFERENCE TO RELATED APPLICATIONS

This non-provisional application claims priority under 35 U.S.C. § 119to U.S. Provisional Application No. 62/677,329 filed May 29, 2018, U.S.Provisional Application No. 62/824,531 filed Mar. 27, 2019, and U.S.Provisional Application No. 62/824,540 filed Mar. 27, 2019. The entirecontents of the foregoing applications are hereby incorporated byreference.

TECHNICAL FIELD

Example embodiments relate to a heat dissipation device, moreparticularly a heat dissipation plate having a capillary structure and amethod for manufacturing the same.

BACKGROUND

As technology progresses, performance of electronic components hasincreased, and as a result, a large amount of heat is released duringoperation. To dissipate the generated heat, heat dissipation devices,such as a heat dissipation plate, are used with the electroniccomponents. The heat dissipation plate includes a circulation channelfilled with coolant. When the heat dissipation plate is in thermalcontact with a heat source, such as an electrical component, the coolantin the circulation channel absorbs heat generated by the electroniccomponent to cool the electronic component.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is best understood from the following detaileddescription when read with the accompanying figures. It is emphasizedthat, in accordance with the standard practice in the industry, variousfeatures are not drawn to scale and are used for illustration purposesonly. In fact, the dimensions of the various features may be arbitrarilyincreased or reduced for clarity of discussion.

FIG. 1 is a perspective view of a heat dissipation plate according to anexemplary embodiment.

FIG. 2 is an exploded view of the heat dissipation plate in FIG. 1.

FIG. 3 is a partial cross-sectional view of the heat dissipation platein FIG. 1.

FIG. 4 is an exploded view of a heat dissipation plate according to anexemplary embodiment.

FIG. 5 is a schematic view of the heat dissipation plate in FIG. 1 inthermal contact with two heat sources and including a coolant;

FIG. 6 is a perspective view of a heat dissipation plate according to anexemplary embodiment.

FIG. 7 is an exploded view of the heat dissipation plate in FIG. 6.

FIG. 8 is a partial cross-sectional view of the heat dissipation platein FIG. 6.

FIG. 9 is a schematic view of the heat dissipation plate in FIG. 6 inthermal contact with two heat sources and including a coolant.

FIG. 10 is a perspective view of a heat dissipation plate according toan exemplary embodiment.

FIG. 11 is an exploded view of the heat dissipation plate in FIG. 10.

FIG. 12 is a partial cross-sectional view of the heat dissipation platein FIG. 10.

FIG. 13 is a schematic view of the heat dissipation plate in FIG. 10 inthermal contact with two heat sources and including a coolant.

FIG. 14 is a perspective view of a roll-bonded heat exchanger accordingto an exemplary embodiment.

FIG. 15 is a front view of the roll-bonded heat exchanger in FIG. 14.

FIG. 16 is a partial cross-sectional view of the roll-bonded heatexchanger of FIG. 14 taken along line 16-16 in FIG. 15.

FIG. 17 is a partial cross-sectional view of a roll-bonded heatexchanger according to an exemplary embodiment.

FIG. 18 is a partial cross-sectional view of a roll-bonded heatexchanger according to an exemplary embodiment.

FIG. 19 is a partial cross-sectional view of a roll-bonded heatexchanger according to an exemplary embodiment.

FIG. 20 is a partial cross-sectional view of a roll-bonded heatexchanger according to an exemplary embodiment.

FIG. 21 is a partial cross-sectional view of a roll-bonded heatexchanger according to an exemplary embodiment.

FIG. 22 is a partial cross-sectional view of a roll-bonded heatexchanger according to an exemplary embodiment.

FIG. 23 is a partial cross-sectional view of a roll-bonded heatexchanger according to an exemplary embodiment.

FIG. 24 is a partial cross-sectional view of a roll-bonded heatexchanger according to an exemplary embodiment.

FIG. 25 is a partial cross-sectional view of a roll-bonded heatexchanger according to an exemplary embodiment.

FIG. 26 is a partial cross-sectional view of a roll-bonded heatexchanger according to an exemplary embodiment.

FIGS. 27, 28, and 29 are views showing a process of forming capillarystructure in the roll-bonded heat exchanger in FIG. 26.

DETAILED DESCRIPTION

It is to be understood that the following disclosure provides manydifferent embodiments, and examples, for implementing different featuresof the disclosure. Specific embodiments or examples of components andarrangements are described below to simplify the present disclosure.These are, of course, merely examples and are not intended to belimiting. For example, dimensions of elements are not limited to thedisclosed range or values, but may depend upon process conditions and/ordesired properties of the device. Moreover, the formation of a firstfeature over or on a second feature in the description that follows mayinclude embodiments in which the first and second features are formed indirect contact, and may also include embodiments in which additionalfeatures may be formed interposing the first and second features, suchthat the first and second features may not be in direct contact. Variousfeatures may be arbitrarily drawn in different scales for simplicity andclarity.

Further, spatially relative terms, such as “beneath,” “below,” “lower,”“above,” “upper” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. The spatiallyrelative terms are intended to encompass different orientations of thedevice in use or operation in addition to the orientation depicted inthe figures. The device may be otherwise oriented (rotated 90 degrees orat other orientations) and the spatially relative descriptors usedherein may likewise be interpreted accordingly. In addition, the term“made of” may mean either “comprising” or “consisting of.”

Embodiments in the present disclosure are directed to a heat dissipationdevice that improves the circulation of cooling fluid (also referred toas a coolant) in the heat dissipation device. The heat dissipationdevice, according to the example embodiments, permits the cooling fluidto flow in a direction opposite the force of gravity when the heatdissipation device is not completely filled with cooling fluid. In priorart heat dissipating devices, when a heat source is in thermal contactwith the heat dissipation device above the surface of the cooling fluidin the heat dissipation device, the coolant circulating in the fluidchannel of the heat dissipation device does not flow towards the heatsource due to the gravitational force. Thus, heat generated by the heatsource cannot be effectively dissipated by the cooling fluid.

FIG. 1 is a perspective view of a heat dissipation device 10 accordingto an exemplary embodiment. FIG. 2 is an exploded view of the heatdissipation device 10 in FIG. 1. FIG. 3 is a partial cross-sectionalview of the heat dissipation device 10 in FIG. 1. In an example, and asillustrated, the heat dissipation device 10 in FIG. 1 is a plate-typedevice, referred to herein as a heat dissipation plate 10. It should benoted that embodiments as discussed herein are not applicable only toplate-type heat dissipation devices, but are equally applicable to heatdissipation devices of any shape, without departing from the spirit andscope of the disclosure.

As illustrated, the heat dissipation plate 10 includes a first plate100, a second plate 200, and a capillary structure 300. The first plate100 and the second plate 200 are disposed opposite each other and thecapillary structure 300 is disposed between the first plate 100 and thesecond plate 200.

The first plate 100 has a first longitudinal edge (or side) 101 and asecond longitudinal edge (or side) 102 opposite each other. The firstplate 100 further has a first plurality of inclined or angled grooves110 disposed in the longitudinal direction (or the X-direction inFIG. 1) and spaced apart from each other. Each groove 110 is a recess(or a concavity) that extends into the body of the first plate 100 andextends (in the Y-direction) between the first longitudinal edge 101 andthe second longitudinal edge 102. Referring to FIG. 2, each groove 110includes a first end 151 adjacent the first longitudinal edge 101 and asecond end 152 adjacent the second longitudinal edge 102 and oppositethe first end 151. As illustrated, the first end 151 is located higherthan the second end 152, and, as a result, the grooves 110 are disposedat an angle in the first plate 100.

The first plate 100 also includes a first longitudinal groove 120 and asecond longitudinal groove 130, both extending in the X-direction. Thefirst longitudinal groove 120 is located adjacent the first longitudinaledge 101 and the second longitudinal groove 130 is located adjacent thesecond longitudinal edge 102. The first ends 151 of the grooves 110 arein fluid communication with the first longitudinal groove 120 and thesecond ends 152 of the grooves 110 are in fluid communication with thesecond longitudinal groove 130. Thus, the grooves 110 are in fluidcommunication with each other through the first and second longitudinalgrooves 120 and 130. In FIG. 2, the first plate 100 is shown disposedvertically, and the direction indicated by the arrow G indicates thedirection of the force of gravity.

The second plate 200 has a first longitudinal edge 201 and a secondlongitudinal edge 202 opposite each other. The second plate 200 alsoincludes a second plurality of inclined or angled grooves 210 disposedin the longitudinal direction (or the X-direction in FIG. 1) and spacedapart from each other. Each groove 210 is a recess (or concavity) thatextends into the body of the second plate 200 and extends (in theY-direction) between the first longitudinal edge 201 and the secondlongitudinal edge 202. Referring to FIG. 2, each groove 210 includes afirst end 171 adjacent the first longitudinal edge 201 and a second end172 adjacent the second longitudinal edge 202 and opposite the first end171. The first end 171 is located higher than the second end 172, and,as a result, the grooves 210 are disposed at an angle in the secondplate 200.

The second plate 200 includes a first longitudinal groove 220 and asecond longitudinal groove 230, both extending in the X-direction. Thefirst longitudinal groove 220 is located adjacent the first longitudinaledge 201 and the second longitudinal groove 230 is located adjacent thesecond longitudinal edge 202. The first ends 171 of the grooves 210 arein fluid communication with the first longitudinal groove 220 and thesecond ends 172 of the grooves 210 are in fluid communication with thesecond longitudinal groove 230. Thus, the grooves 210 are in fluidcommunication with each other through the first and second longitudinalgrooves 220 and 230.

As illustrated in FIG. 1, the second plate 200 is coupled to the firstplate 100, such that the grooves 110 are parallel to the grooves 210 andmisaligned with the grooves 210. In such an arrangement, grooves 110 andgrooves 210 are offset from each other. In one embodiment, grooves 110and grooves 210 partially overlap each other. In another embodiment, thegroove 210 is located between two grooves 110. Further, in thisarrangement, the first and second longitudinal grooves 120 and 130 ofthe first plate 100 are respectively aligned and fluidly connected tothe first and second longitudinal grooves 220 and 230 of the secondplate 200. As such, the grooves 110 and the grooves 210 are connected toeach other via the first and second longitudinal grooves 120 and 130 ofthe first plate 100 and the first and second longitudinal grooves 220and 230 of the second plate 200 to form a fluid channel C (FIG. 3) thatallows coolant to flow therethrough. The fluid channel C is continuousthroughout the heat dissipation plate 10, although, as discussed below,the entire fluid channel C may not be filled with coolant L.

Furthermore, the heat dissipation plate 10 includes an inlet O definedby the second longitudinal groove 130 of the first plate 100 and thesecond longitudinal groove 230 of the second plate 200. The inlet Opermits coolant to be introduced into the fluid channel C. Asillustrated, the inlet O is aligned with the second longitudinal groove130 and the second longitudinal groove 230.

The capillary structure 300 is located in the fluid channel C. Thecoolant does not completely fill the fluid channel C and only part ofthe fluid channel C is occupied by the coolant. The capillary structure300 extends from a position below a surface of the coolant to a positionabove the surface of the coolant. As such, the capillary structure 300is partially immersed in the coolant. In one embodiment, the capillarystructure 300 is located in the grooves 210 and both of the first andsecond longitudinal grooves 220 and 230 of the second plate 200.However, embodiments are not limited in this regard. In otherembodiments, the capillary structure 300 may be located in the grooves210 and only one of the first and second longitudinal grooves 220 and230 of the second plate 200. For example, as shown in FIG. 4, acapillary structure 300A is located in the grooves 210 and the secondlongitudinal groove 230 of the second plate 200. The groove 110 may bereferred to as a vapor channel and groove 210 may be referred to as theflow channel.

In some embodiments, the capillary structure 300 may not completelyoverlap the grooves 210 and the first and second longitudinal grooves220 and 230 of the second plate 200. Stated otherwise, the capillarystructure 300 may not completely line the grooves 210 and the first andsecond longitudinal grooves 220 and 230 of the second plate 200. Inanother embodiment, the capillary structure 300 may partially overlap orline the grooves 210 and the first and second longitudinal grooves 220and 230 of the second plate 200. In yet another embodiment, if the firstlongitudinal groove 220 is adjacent a heat generating source, then thegroove 210 and first longitudinal groove 220 above the surface S of thecoolant L are completely lined with the capillary structure 300. Thesecond longitudinal groove 230 does not include a capillary structure.Similarly, if the second longitudinal groove 230 is adjacent a heatgenerating source, then the groove 210 and second longitudinal groove230 above the surface S of the coolant L are completely lined with thecapillary structure 300. The first longitudinal groove 220 does notinclude a capillary structure.

FIG. 3 illustrates a partial cross-sectional view of the heatdissipation plate 10 including the capillary structure 300 in the fluidchannel C defined by groove 210 of the second plate 200. As illustrated,the capillary structure 300 lines the groove 210, but does notcompletely fill (or occupy) the fluid channel C.

FIG. 5 is a schematic view of the heat dissipation plate 10 of FIG. 1 inthermal contact with two heat sources H1 and H2 and including coolant L.As illustrated in FIG. 5, the coolant L partially fills the fluidchannel C. The heat dissipation plate 10 is positioned vertically, andthe first heat source H1 and the second heat source H2 are in thermalcontact with the heat dissipation plate 10 and respectively locatedbelow and above the surface S of the coolant L. When the first heatsource H1 is generating heat (e.g., during operation), the coolant L inliquid form absorbs heat generated by the first heat source H1 andchanges to vapor that flows in a direction opposite the arrow G to arelatively cooler portion of the heat dissipation plate 10. Because, thesecond heat source H2 is also generating heat, the relatively coolerportion of the heat dissipation plate 10 is to the right in FIG. 5adjacent to the second longitudinal groove 230. The coolant L in vaporform condenses to liquid again and flows back to the lower portion ofthe fluid channel C (e.g., the relatively hotter portion of the heatdissipation plate 10) along the second longitudinal groove 230. Thecirculation of the coolant in the heat dissipation plate 10 is indicatedby the arrow F.

Due to the heat generated by the second heat source H2 (e.g., duringoperation), the coolant is drawn from the lower portion of the fluidchannel C via the capillary structure 300 to the second heat source H2.The coolant L changes to vapor that flows in the direction indicated bythe arrow D1 towards the relatively cooler portion of the heatdissipation plate 10. The coolant in vapor form flowing away from thesecond heat source H2 condenses to liquid due to the relatively coolerportion of the heat dissipation plate 10. The condensed coolant inliquid form is transported toward the heat source H2 as indicated by thearrow D2. As such, the coolant flow due to the second heat source H2 hasa relatively smaller circulation path compared to coolant flow whendissipating heat from the first heat source H1.

Accordingly, the heat dissipation plate 10 is able to dissipate heatgenerated by a heat source whether it is located below or above thesurface of the coolant.

The heat dissipation plate 10 can be manufactured using a compositeplate including a welding material, or by using a non-composite (e.g.,aluminum) plate not including a welding material.

In the method using a composite plate including a welding material, oneor more stamping processes are performed on two plates both having thewelding material to obtain the first plate 100 having the firstplurality of inclined grooves 110 and the first and second longitudinalgrooves 120 and 130, and to obtain the second plate 200 having thesecond plurality of inclined grooves 210 and the first and secondlongitudinal grooves 220 and 230.

The shapes and sizes of the grooves 110 and 210 and the longitudinalgrooves 120, 130, 220, and 230 are not limited to any particular shapeand size, and the shapes and sizes can vary as required by design and/orapplication. In some embodiments, the grooves 110 and 120 and thelongitudinal grooves 120, 130, 220, and 230 may have different shapesand/or sizes in order to create a pressure difference for controllingthe flowing direction of the vaporized coolant.

For example, the one or more grooves 110 of the first plate 100 may havea different cross-sectional shape or size. Similarly, the grooves 110and the longitudinal grooves 120 and 130 of the first plate 100 may havea different cross-sectional shape or size. In other examples, thegrooves 110 of the first plate 100 and the grooves 210 of the secondplate 200 may have a different cross-sectional shape or size.

Then, powder is deposited in the second grooves 210 and the first andsecond longitudinal grooves 220 and 230 of the second plate 200 and thesecond plate 200 is heated to form the capillary structure 300 viasintering.

At the same time, a welding flux is provided on a welding surface of thesecond plate 200 that is not covered by the powder in order to clean thewelding surface, and thereby improve the welding quality. However, inother embodiments, the welding flux is omitted.

The first plate 100 and the second plate 200 are coupled to each other(e.g., the plates may be stacked over each other) and are aligned witheach other by a fixture and then welded. Thus, the welding and sinteringoperations are performed simultaneously. The fixture resists the stressoccurring during the welding process and thus prevents the deformationof the first plate 100 and the second plate 200. The fixture is made ofgraphite or other materials which do not interact with the weldingmaterial.

Then, the first plate 100 and the second plate 200 are heated to meltthe welding material and fix the first plate 100 and the second plate200 to each other. In addition, the heating also sinters the powder toobtain the capillary structure 300.

Then, air in the fluid channel C is removed through the inlet O and thencoolant L is filled into the fluid channel C through the inlet O. In oneembodiment, a pipe is welded to the inlet O to suck out the air from thefluid channel C and to then introduce coolant L into the fluid channelC.

In the method using a non-composite plate not including a weldingmaterial (e.g., welding by using a solder), one or more stampingprocesses are performed on two plates not having welding material so asto obtain the first plate 100 having the first plurality of inclinedgrooves 110 and the first and second longitudinal grooves 120 and 130,and to obtain the second plate 200 having the second plurality ofinclined grooves 210 and the first groove 220 and the second groove 230.

The shapes and sizes of the grooves 110 and 210 and the longitudinalgrooves 120, 130, 220, and 230 are not limited to any particular shapeand size, and the shapes and sizes can vary as required by design and/orapplication. In some embodiments, the grooves 110 and 120 and thelongitudinal grooves 120, 130, 220, and 230 may have different shapesand/or sizes in order to create a pressure difference for controllingthe flowing direction of the vaporized coolant.

For example, the one or more grooves 110 of the first plate 100 may havea different cross-sectional shape or size. Similarly, the grooves 110and the longitudinal grooves 120 and 130 of the first plate 100 may havea different cross-sectional shape or size. In other examples, thegrooves 110 of the first plate 100 and the grooves 210 of the secondplate 200 may have a different cross-sectional shape or size.

Then, powder is deposited in the grooves 210 and the first and secondlongitudinal grooves 220 and 230 of the second plate 200. The powder issintered to obtain the capillary structure 300. As discussed above, inone embodiment, the powder may be disposed in the grooves 210 and onlyone of the first and second longitudinal grooves 220 and 230 of thesecond plate 200.

Then, a welding material is provided on a surface to be welded of thesecond plate 200 that is not covered by the powder.

A welding flux is then provided on the welding material disposed on thesecond plate 200 to improve the welding quality.

The first plate 100 and the second plate 200 are coupled to each other(e.g., the plates may be stacked over each other) and are aligned witheach other by a fixture. The fixture resists the stress occurring duringthe welding process and thus prevents the deformation of the first plate100 and the second plate 200. The fixture is made of graphite or othermaterials which do not interact with the welding material.

The first plate 100 and the second plate 200 are welded together. Air inthe fluid channel C is removed through the inlet O and coolant L isintroduced into the fluid channel C through the inlet O. In oneembodiment, a pipe may be welded to the inlet O of the heat dissipationplate 10 to and air may be sucked out of the fluid channel C via thepipe. Coolant L is then introduced into the fluid channel C using thepipe.

The capillary structure 300 is formed by disposing the powder at thegrooves 210 and the first and second longitudinal grooves 220 and 230 ofthe second plate 200 and sintering it, but the present disclosure is notlimited thereto. In other embodiments, the capillary structure may befirst formed from the capillary powder, and then installed into thegrooves 210 and the first and second longitudinal grooves 220 and 230 ofthe second plate 200. As a result, the capillary structure can be formedin the first plate 100 and the second plate 200.

FIG. 6 is a perspective view of a heat dissipation plate 10 a accordingto another embodiment. FIG. 7 is an exploded view of the heatdissipation plate 10 a in FIG. 6. FIG. 8 is a partial cross-sectionalview of the heat dissipation plate 10 a in FIG. 6.

The heat dissipation plate 10 a includes a first plate 100 a, a secondplate 200 a and a capillary structure 300 a. The first plate 100 a andthe second plate 200 a are disposed opposite each other and thecapillary structure 300 is disposed between the first plate 100 a andthe second plate 200 a.

The first plate 100 a has a first longitudinal edge (or side) 101 a anda second longitudinal edge (or side) 102 a opposite each other. Thefirst plate 100 a further has a first plurality of inclined or angledgrooves 110 a disposed in the longitudinal direction (or the X-directionin FIG. 6) and spaced apart from each other. Each groove 110 a is arecess (or a concavity) that extends into the body of the first plate100 a and extends (in the Y-direction) between the first longitudinaledge 101 a and the second longitudinal edge 102 a. Referring to FIG. 7,each groove 110 a includes a first end 151 a adjacent the firstlongitudinal edge 101 a and a second end 152 a adjacent the secondlongitudinal edge 102 a and opposite the first end 151 a. Asillustrated, the first end 151 a is located lower than the second end152 a, and, as a result, the grooves 110 a are disposed at an angle inthe first plate 100 a. It will be understood that the grooves 110 a areconsidered angled or inclined with reference to the top (or bottom) edgeof the first plate 100 a.

The first plate 100 a also includes a longitudinal groove 130 aextending in the X-direction. The longitudinal groove 130 a is locatedadjacent the second longitudinal edge 102 a. The second ends 152 a ofthe grooves 110 a are in fluid communication with the longitudinalgroove 130 a. Thus, the grooves 110 a are in fluid communication witheach other through the longitudinal groove 130 a. In FIG. 6, the firstplate 100 a is shown disposed vertically, and the direction indicated bythe arrow G is the direction of the force of gravity.

The second plate 200 a has a first longitudinal edge 201 a and a secondlongitudinal edge 202 a opposite each other. The second plate 200 a alsoincludes a second plurality of inclined or angled grooves 210 a disposedin the longitudinal direction (or the X-direction in FIG. 6) and spacedapart from each other. Each groove 210 a is a recess (or concavity) thatextends into the body of the second plate 200 a and extends (in theY-direction) between the first longitudinal edge 201 a and the secondlongitudinal edge 202 a. Referring to FIG. 7, each groove 210 a includesa first end 171 a adjacent the first longitudinal edge 201 a and asecond end 172 a adjacent the second longitudinal edge 202 a andopposite the first end 171 a. The first end 171 a is located higher thanthe second end 172 a, and, as a result, the grooves 210 a are disposedat an angle in the second plate 200 a. Referring to FIG. 7, it will beunderstood that the longitudinal grooves 110 a and 210 a are orientatedin opposite directions. It will be understood that the grooves 210 a areconsidered angled or inclined with reference to the top (or bottom) edgeof the second plate 200 a.

The second plate 200 a includes a longitudinal groove 220 a extending inthe X-direction. The longitudinal groove 220 a is located adjacent thefirst longitudinal edge 201 a. The first ends 171 a of the grooves 210are in fluid communication with the longitudinal groove 220 a. Thus, thegrooves 210 a are in fluid communication with each other through thelongitudinal groove 220 a.

As illustrated in FIG. 6, the second plate 200 a is coupled to the firstplate 100 a such that portions of the inclined grooves 110 a andportions of the inclined grooves 210 a intersect each other and theinclined grooves 110 a are connected in fluid communication with eachother via the inclined groove 210 a and the longitudinal groove 130 a.The inclined grooves 110 a, the inclined grooves 210 a, the longitudinalgroove 120 a and the longitudinal groove 220 a together form a fluidchannel C that allows coolant L to flow therethrough. The fluid channelC is continuous throughout the heat dissipation plate 10 a, although, asdiscussed below, the entire fluid channel C may not be filled withcoolant L.

As illustrated, the longitudinal groove 130 a and the longitudinalgroove 220 a are located at two opposite ends of the grooves 110 a, butembodiments are not limited in this regard. In other embodiments, thelongitudinal groove 130 a and the longitudinal groove 220 a may belocated at the same end of the grooves 110 a.

The heat dissipation plate 10 a has an inlet O formed by the topmostgroove 110 a and the topmost groove 210 a, each proximate the top of theheat dissipation plate 10 a. The inlet O allows coolant L to beintroduced into the fluid channel C.

The capillary structure 300 a is located in the fluid channel C. Thecoolant does not completely fill the fluid channel C and only part ofthe fluid channel C is occupied by the coolant L. The capillarystructure 300 a extends from below a surface S of the coolant L to abovethe surface S of the coolant L. Stated otherwise, the capillarystructure 300 a is partially submerged in coolant. As illustrated, thecapillary structure 300 a is located in the grooves 210 a and thelongitudinal groove 220 a of the second plate 200 a.

However embodiments are not limited in this regard. In otherembodiments, the capillary structure 300 a may be disposed in the firstplate 100 a. In other embodiments, the heat dissipation plate 10 a mayhave two capillary structures respectively disposed on the first plate100 a and the second plate 200 a.

Furthermore, the capillary structure 300 a may not be completelyoverlapped with the grooves 210 a and the longitudinal groove 220 a ofthe second plate 200 a. Stated otherwise, the capillary structure 300 amay not completely line the grooves 210 a and the longitudinal groove220 a. In another embodiment, the capillary structure 300 a maypartially overlap or line the grooves 210 a and the longitudinal groove220 a of the second plate 200 a.

FIG. 8 illustrates a partial cross-sectional view of the heatdissipation plate 10 a including the capillary structure 300 a in thefluid channel C defined by grooves 110 a and 210 a. As illustrated, thecapillary structure 300 a lines the groove 210 a, but does notcompletely fill (or occupy) the fluid channel C.

FIG. 9 is a schematic view of the heat dissipation plate 10 a in FIG. 6in thermal contact with two heat sources H1 and H2 and including coolantL. In FIG. 9, coolant L partially fills the fluid channel C. The heatdissipation plate 10 a is positioned vertically, and the first heatsource H1 and the second heat source H2 are in thermal contact with theheat dissipation plate 10 a and respectively located below and above thesurface S of the coolant L. When the first heat source H1 is generatingheat (e.g., during operation), the coolant L in liquid form absorbs heatgenerated by the first heat source H1 and changes to vapor that flows ina direction opposite the arrow G to a relatively cooler portion of theheat dissipation plate 10 a. The coolant L in vapor form condenses toliquid and flows back to the lower portion of the fluid channel C (e.g.,the relatively hotter portion of the heat dissipation plate 10 a). Thecirculation of the coolant in the heat dissipation plate 10 a isindicated by the arrow F.

Due to the heat generated by the second heat source H2, coolant is drawnfrom the lower portion of the fluid channel C via the capillarystructure 300 a to the second heat source H2. The coolant L changes tovapor that flows in the direction of arrow D1 towards the relativelycooler portion of the heat dissipation plate 10 a. The coolant in thevapor form flowing away from the second heat source H2 condenses toliquid due to the relatively cooler portion of the heat dissipationplate 10 a. The condensed coolant is transported towards the heat sourceH2 as indicated by the arrow D2. As such, the coolant flow due to thesecond heat source H2 has a relatively smaller circulation path comparedto the coolant flow due to the first heat source H1.

Accordingly, the heat dissipation plate 10 a is able to dissipate heatgenerated by the heat source whether it is located below or above thesurface of the coolant.

The manufacturing process of the heat dissipation plate 10 a is similarto that of the heat dissipation plate 10, thus a discussion thereof isomitted for the sake of brevity.

FIG. 10 is a perspective view of a heat dissipation plate 10 b accordingto an exemplary embodiment. FIG. 11 is an exploded view of the heatdissipation plate 10 b in FIG. 10. FIG. 12 is a partial cross-sectionalview of the heat dissipation plate 10 b in FIG. 10.

The heat dissipation plate 10 b includes a first plate 100 b, a secondplate 200 b and a plurality of capillary structures 300 b. The firstplate 100 b and the second plate 200 b are disposed opposite each otherand the capillary structures 300 b are disposed between the first plate100 b and the second plate 200 b.

The first plate 100 b has a first longitudinal edge (or side) 101 b anda second longitudinal edge (or side) 102 b opposite each other. Thefirst plate 100 b further has a first plurality of inclined or angledgrooves 110 b disposed in the longitudinal direction (or the X-directionin FIG. 10) and spaced apart from each other. Each groove 110 b is arecess (or a concavity) that extends into the body of the first plate100 b and extends (in the Y-direction) between the first longitudinaledge 101 b and the second longitudinal edge 102 b. Referring to FIG. 11,each groove 110 b includes a first end 151 b adjacent the firstlongitudinal edge 101 b and a second end 152 b adjacent the secondlongitudinal edge 102 b and opposite the first end 151 b. Asillustrated, the first end 151 b is located lower than the second end152 b, and, as a result, the grooves 110 b are disposed at an angle inthe first plate 100 b. It will be understood that the grooves 110 b areconsidered angled or inclined with reference to the top (or bottom) edgeof the first plate 100 b.

In FIG. 10, the first plate 100 b is shown disposed vertically, and thedirection indicated by the arrow G is the direction of the force ofgravity.

The second plate 200 b has a first longitudinal edge 201 b and a secondlongitudinal edge 202 b opposite each other. The second plate 200 bincludes a second plurality of inclined or angled grooves 210 b disposedin the longitudinal direction (or the X-direction in FIG. 6) and spacedapart from each other. Each groove 210 b is a recess (or concavity) thatextends into the body of the second plate 200 b and extends (in theY-direction) between the first longitudinal edge 201 b and the secondlongitudinal edge 202 b. Referring to FIG. 11, each groove 210 bincludes a first end 171 b adjacent the first longitudinal edge 201 band a second end 172 b adjacent the second longitudinal edge 202 b andopposite the first end 171 b. The first end 171 b is located higher thanthe second end 172 b, and, as a result, the grooves 210 b are disposedat an angle in the second plate 200 b. It will be understood that thegrooves 210 b are considered angled or inclined with reference to thetop (or bottom) edge of the second plate 200 b. Referring to FIG. 11, itwill be understood that the grooves 110 b and 220 b are orientated inopposite directions.

As illustrated in FIG. 10, the second plate 200 b is coupled to thefirst plate 100 b such that portions of the first grooves 110 b andportions of the inclined grooves 210 b intersect each other and theinclined grooves 110 b are connected in fluid communication with eachother via the inclined grooves 210 b. The inclined grooves 110 b and theinclined grooves 210 b together form a fluid channel C that allowscoolant L to flow therethrough. The fluid channel C is continuousthroughout the heat dissipation plate 10 b, although, as discussedbelow, the entire fluid channel C may not be filled with coolant L.

The heat dissipation plate 10 b has an inlet O formed by topmost groove110 b and the topmost groove 210 b, each located proximate the top ofthe heat dissipation plate 10 b. The inlet O allows coolant L to beintroduced into the fluid channel C.

The capillary structures 300 b are located in the fluid channel C. Thecoolant L does not completely fill the fluid channel C and only part ofthe fluid channel C is occupied by the coolant L. The capillarystructures 300 b are arranged from below a surface S of the coolant L toabove the surface S of the coolant L. Stated otherwise, the capillarystructure 300 b is partially submerged in coolant. In one embodiment andas illustrated, the capillary structures 300 b are located incorresponding grooves 210 b of the second plate 200 b. However,embodiments are not restricted in this regard. In other embodiments, thecapillary structures 300 b may be disposed in the first plate 100 b. Instill other embodiments, the capillary structures 300 b may be disposedin both the first plate 100 b and the second plate 200 b.

The capillary structures 300 b may not completely overlapped or linedwith the grooves 210 b of the second plate 200 b. In yet anotherembodiment, the capillary structures 300 b may partially overlap or linethe second grooves 210 b of the second plate 200 b.

FIG. 12 illustrates a partial cross-sectional view of the heatdissipation plate 10 b including the capillary structure 300 b in thefluid channel C defined by grooves 110 b and 210 b. As illustrated, thecapillary structure 300 b lines the groove 210 b, but does notcompletely fill (or occupy) the fluid channel C.

FIG. 13 is a schematic view of the heat dissipation plate 10 b in FIG.10 in thermal contact with two heat sources H1 and H2 and includingcoolant L. In FIG. 13, coolant L partially fills the fluid channel C.The heat dissipation plate 10 b is positioned vertically, and the firstheat source H1 and the second heat source H2 are in thermal contact withthe heat dissipation plate 10 b and respectively located below and abovethe surface S of the coolant L. When the first heat source H1 isgenerating heat (e.g., during operation), the coolant L in liquid formabsorbs heat generated by the first heat source H1 and changes to vaporthat flows in a direction opposite the arrow G to a relatively coolerportion of the heat dissipation plate 10 b. The coolant L in vapor formcondenses to the liquid and flows back to the lower portion of the fluidchannel C (e.g., the relatively hotter portion of the heat dissipationplate 10 b). The circulation of the coolant in the heat dissipationplate 10 b is indicated by the arrow F.

Due to the heat generated by the second heat source H2, coolant is drawnfrom the lower portion of the fluid channel C via the capillarystructure 300 b to the second heat source H2. The coolant L changes tovapor that flows in the direction of arrow D1 towards the relativelycooler portion of the heat dissipation plate 10 b. The coolant in vaporform flowing away from the second heat source H2 condenses to liquid dueto the relatively cooler portion of the heat dissipation plate 10 b. Thecondensed coolant is transported towards the second heat source H2 asindicated by the arrow D2. As such, the coolant flow due to the secondheat source H2 has a relatively smaller circulation path compared to thecoolant flow due to the first heat source H1.

Accordingly, the heat dissipation plate 10 b is able to dissipate heatgenerated by the heat sources whether it is located below or above thesurface of the coolant.

The manufacturing process of the heat dissipation plate 10 b is similarto that of the heat dissipation plate 10, and therefore a discussionthereof is omitted for the sake of brevity.

In the aforementioned example embodiments, the first plate and thesecond plate both have inclined grooves, but the disclosure is notlimited in this regard. In other embodiments, only one of the firstplate and the second plate may have inclined grooves.

According to the heat dissipation plate according to example embodimentsdiscussed above, the capillary structure is disposed in the fluidchannel, such that the coolant is able to flow against the force ofgravity via the capillary structure and to the portion of the fluidchannel close to the heat source located above the surface of thecoolant. Therefore, the heat dissipation plate according to exampleembodiments is capable of dissipating heat generated by the heat sourcelocated below or above the surface of the coolant.

FIG. 14 is a perspective view of a roll-bonded heat exchanger 140 aaccording to an exemplary embodiment. FIG. 15 is a front view of theroll-bonded heat exchanger 140 a viewed in the direction of arrow M.FIG. 16 is a partial cross-sectional view of the roll-bonded heatexchanger 140 a along line 16-16 in FIG. 15. It should be noted that,although example embodiments are discussed below with reference to aroll-bonded heat exchanger, the example embodiments are not limitedthereto and are equally applicable to other types of heat dissipatingdevices without departing from the spirit and scope of the disclosure.

The roll-bonded heat exchanger 140 a dissipates heat generated by a heatsource (e.g., an electronic circuit) that is in thermal contact with theroll-bonded heat exchanger 140 a. The heat source is, for example, acentral processing unit (CPU), but embodiments are not limited thereto.Referring to FIG. 16, the roll-bonded heat exchanger 140 a includes aheat conducting plate structure 1400 a and a capillary structure 1610 aenclosed within the heat conducting plate structure 1400 a. The heatconducting plate structure 1400 a includes a channel 1405 a and anopening 1406 a that are connected to each other. The channel 1405 a issized and shaped (or otherwise configured) to include a coolant (notshown). The coolant is, for example, water or refrigerant, butembodiments are not limited thereto. The coolant may occupy about 30 to70 percent of the volume of the channel 1405 a. However, in otherembodiments, the volume of the channel 1405 a occupied by the coolantcan be more or less as required. The coolant can be introduced into thechannel 1405 a via the opening 1406 a.

The heat conducting plate structure 1400 a includes a first plate 1410 aand a second plate 1420 a sealingly bonded with each other. The firstplate 1410 a includes a first surface 1412 a that defines (or otherwiseincludes) a first recess (or a concavity) 1411 a. The second plate 1420a includes a second surface 1422 a that is planar. The second surface1422 a faces the first surface 1412 a when the first plate 1410 a andthe second plate 1420 a are bonded with each other. As illustrated, insuch an arrangement, the first recess 1411 a is located between thefirst surface 1412 a and the second surface 1422 a. The first surface1412 a and the second surface 1422 a cooperatively define the channel1405 a.

As shown in FIG. 15, the roll-bonded heat exchanger 140 a includes arefrigerant area A1, a cooling area A2 and a heat absorbing area A3. Therefrigerant area A1 is located below the heat absorbing area A3, and thecooling area A2 is located between the refrigerant area A1 and the heatabsorbing area A3. When the roll-bonded heat exchanger 140 a is used todissipate heat from a heat source, the heat absorbing area A3, thecooling area A2, and the refrigerant area A1 are arranged along agravitational direction indicated by the arrow G with the refrigerantarea A1 being the bottom-most portion of the roll-bonded heat exchanger140 a. The refrigerant area A1 of the roll-bonded heat exchanger 140 ais configured to store the coolant. The cooling area A2 of theroll-bonded heat exchanger 140 a is configured to release the heat inthe gas-phase coolant and thereby condense the gas-phase coolant to theliquid-phase coolant. The heat absorbing area A3 of the roll-bonded heatexchanger 140 a is configured to be in thermal contact with the heatsource to absorb the heat generated by the heat source.

The capillary structure 1610 a is located in the channel 1405 a anddisposed on the entire first surface 1412 a and extends from therefrigerant area A1 to the heat absorbing area A3.

When the coolant in the heat absorbing area A3 of the roll-bonded heatexchanger 140 a absorbs the heat generated by the heat source, thecoolant is vaporized to the gas phase. The pressure difference iscreated in the roll-bonded heat exchanger 140 a and this causes thevaporized coolant to flow from the heat absorbing area A3 to the coolingarea A2. Then, the vaporized coolant is condensed to the liquid phase inthe cooling area A2. The liquid-phase coolant flows back to the heatabsorbing area A3 along a direction indicated by the arrow H opposite tothe gravitational direction via the capillary structure 1610 a. Aportion of the liquid-phase coolant also flows to the refrigerant areaA1. The coolant is thus circulated in the channel 1405 a.

In other embodiments, the capillary structure may also be disposed onthe second surface 1422 a of the second plate 1420 a. FIG. 17illustrates a partial cross-sectional view of the roll-bonded heatexchanger 140 a according to an exemplary embodiment. As illustrated, acapillary structure 1610 b is disposed over the entire second surface1422 a of the second plate 1420 a in addition to the capillary structure1610 a being disposed over the entire first surface 1412 a of the firstplate 1410 a. However, embodiments are not limited in this regard and inother embodiments, the capillary structure 1610 b may be disposed ononly portions of the second surface 1422 a.

It should be noted that the number of capillary structures in theroll-bonded heat exchanger 140 a is not limited in any regard. FIG. 18is a partial cross-sectional view of the roll-bonded heat exchanger 140a according to an exemplary embodiment. As shown in FIG. 18, theroll-bonded heat exchanger 140 a includes two capillary structures 1610c and 1620 c spaced apart from each other and arranged adjacent oppositeends of the first surface 1412 a in the first recess 1411 a.

FIG. 19 is a partial cross-sectional view of the roll-bonded heatexchanger 140 a according to an exemplary embodiment. As shown in FIG.19, the roll-bonded heat exchanger 140 a includes a single capillarystructure 1610 d disposed on the first surface 1412 a and in the firstrecess 1411 a and spaced from two opposite edges 1421 d of the firstrecess 1411 a. In one embodiment, the capillary structure 1610 d may belocated centrally in the first recess 1411 a on the first surface 1412a.

FIG. 20 is a partial cross-sectional view of the roll-bonded heatexchanger 140 a according to an exemplary embodiment. As shown in FIG.20, the roll-bonded heat exchanger 140 a includes multiple capillarystructures on the first surface 1412 a in the first recess 1411 a. Asillustrated, the roll-bonded heat exchanger 140 a includes a firstcapillary structure 1610 e, a second capillary structure 1620 e, a thirdcapillary structure 1630 e, and a fourth capillary structure 1640 e onthe first surface 1412 a in the first recess 1411 a. The first capillarystructure 1610 e, the second capillary structure 1620 e, the thirdcapillary structure 1630 e, and the fourth capillary structure 1640 eare spaced apart from each other. The first capillary structure 1610 eand the second capillary structure 1620 e are arranged adjacent twoopposite ends of the first surface 1412 a. The third capillary structure1630 e and fourth capillary structure 1640 e are arranged on the firstsurface 1412 a between the first capillary structure 1610 e and thesecond capillary structure 1620 e.

In example embodiments, the second surface 1422 a of the roll-bondedheat exchanger 140 a may not be planar. FIG. 21 is a partialcross-sectional view of the roll-bonded heat exchanger 140 a accordingto an exemplary embodiment. As shown in FIG. 21, the second surface 1422a of the second plate 1420 a defines (or includes) a second recess (orconcavity) 1421 f. The second recess 1421 f is aligned with the firstrecess 1411 a such that the ends of the first recess 1411 a contact theends of the second recess 1421 f. The first surface 1412 a in the firstrecess 1411 a and the second surface 1422 a in the second recess 1421 fcooperatively define the channel 1405 a of the roll-bonded heatexchanger 140 a. Capillary structure 1610 a is located in the channel1405 a and disposed on the entire first surface 1412 a in the firstrecess 1411 a. However, embodiments are not limited in this regard. Inother embodiments, the capillary structure 1610 a may be disposed onlyon a portion of the first surface 1412 a.

FIG. 22 is a partial cross-sectional view of a roll-bonded heatexchanger according to an exemplary embodiment. Compared to theembodiment shown in FIG. 21, in the embodiment in FIG. 22, capillarystructure 1610 b is disposed on the entire second surface 1422 a inaddition to the capillary structure 1610 a disposed on the entire firstsurface 1412 a. However, embodiments are not limited in this regard. Inother embodiments, the capillary structures 1610 a and 1610 b may bedisposed only on portions of the respective first and second surfaces1412 a and 1422 a.

FIG. 23 is a partial cross-sectional view of a roll-bonded heatexchanger according to an exemplary embodiment. Compared to theembodiment shown in FIG. 22, in the embodiment in FIG. 23, the channel1405 a includes two capillary structures 1610 h and 1620 h spaced apartfrom each other and respectively disposed adjacent the two opposite endsof the first surface 1412 a. However, in other embodiments, capillarystructures 1610 h and 1620 h may be disposed adjacent the two oppositeends of the second surface 1422 a. In still other embodiments, capillarystructures may be disposed on both the first surface 1412 a and thesecond surface 1422 a.

FIG. 24 is a partial cross-sectional view of a roll-bonded heatexchanger 140 a according to an exemplary embodiment. As shown in FIG.24, the roll-bonded heat exchanger 140 a includes a single capillarystructure 210 i disposed on the first surface 1412 a and in the firstrecess 1411 a and spaced from the opposite edges 1421 d of the firstrecess 1411 a. In one embodiment, the capillary structure 210 i may belocated centrally in the first recess 1411 a on the first surface 1412a. However, in other embodiments, the capillary structure 210 i may bedisposed on the second surface 1422 a in the recess 1421 a. In stillother embodiments, capillary structures may be disposed on both thefirst surface 1412 a and the second surface 1422 a.

FIG. 25 is a partial cross-sectional view of the roll-bonded heatexchanger 140 a according to an exemplary embodiment. As shown in FIG.25, the roll-bonded heat exchanger 140 a includes the first capillarystructure 1610 e, the second capillary structure 1620 e, the thirdcapillary structure 1630 e, and the fourth capillary structure 1640 e onthe first surface 1412 a in the first recess 1411 a. The first capillarystructure 1610 e, the second capillary structure 1620 e, the thirdcapillary structure 1630 e, and the fourth capillary structure 1640 eare spaced apart from each other. The first capillary structure 1610 eand the second capillary structure 1620 e are respectively located ontwo opposite ends of the first surface 1412 a. The third capillarystructure 1630 e and fourth capillary structure 1640 e are spaced apartfrom each other and arranged on the first surface 1412 a between thefirst capillary structure 1610 e and the second capillary structure 1620e. However, in other embodiments, the first capillary structure 1610 e,the second capillary structure 1620 e, the third capillary structure1630 e, and the fourth capillary structure 1640 e may be disposed on thesecond surface 1422 a in the recess 1421 a. In still other embodiments,the four capillary structures may be disposed on both the first surface1412 a and the second surface 1422 a.

The capillary structures 1610 a, 1610 b, 1610 c, 1620 c, 1610 d, 1610 e,1620 e, 1630 e, 1640 e, 1610 h, and 1620 h may be made of or otherwiseinclude a metal, such as aluminum, copper, nickel or titanium.Alternatively, the capillary structures 1610 a, 1610 b, 1610 c, 1620 c,1610 d, 1610 e, 1620 e, 1630 e, 1640 e, 1610 h, and 1620 h may be madeof or otherwise include a non-metallic material, such as carbon tube,graphite, glass fiber or polymer. The capillary structures 1610 a, 1610b, 1610 c, 1620 c, 1610 d, 1610 e, 1620 e, 1630 e, 1640 e, 1610 h, and1620 h may include vent holes, grooves, planar or three-dimensionalwoven meshes (or tube bundles), or the combination thereof.

The capillary structures 1610 a, 1610 b, 1610 c, 1620 c, 1610 d, 1610 e,1620 e, 1630 e, 1640 e, 1610 h, and 1620 h may be manufactured by (1)filling powder in the channel 1405 a and sintering the powder, (2)inserting a molded capillary structure in the channel, or (3) placing amolded capillary structure in graphite printing tubes in the bottom andtop metal plates (e.g., plates 1410 a and 1420 a). Briefly, in graphiteprinting, a pre-determined pattern of the capillary structures isprinted on surfaces of the top and bottom plates prior to roll bondingthe plates. This prevents the top and bottom plates from completelybonded together.

The capillary structures 1610 a, 1610 b, 1610 c, 1620 c, 1610 d, 1610 e,1620 e, 1630 e, 1640 e, 1610 h, and 1620 h may also be manufactured bydirectly replacing the material of the graphite printing tubes by thecapillary structure made from a carbon tube or polymer, a stampingprocess, sandblasting surfaces of the bottom and top metal plates (e.g.,plates 1410 a and 1420 a), or etching the surfaces of the bottom and topmetal plates (e.g., plates 1410 a and 1420 a).

FIG. 26 is an isometric view of a roll-bonded heat exchanger 140 kaccording to an exemplary embodiment. FIG. 27, FIG. 28, and FIG. 29 areviews showing a process of forming a capillary structure of theroll-bonded heat exchanger 140 k in FIG. 26. As illustrated, aroll-bonded heat exchanger 140 k includes a heat conducting plate body1400 k having a plurality of angled channels 1405 k formed as grooves(or recesses) in the bottom plate of the heat conducting plate body 1400k and a plurality of angled channels 1403 k formed as grooves (orrecesses) in the top plate of the heat conducting plate body 1400 k thatare orientated opposite angled channels 1405 k. The angled channels 1403k and 1405 k extend in a straight line (without any bends or curves) inthe body of the roll-bonded heat exchanger 140 k. Each angled channel1405 k includes a single capillary structure 1610 k. It will beunderstood that the angled channels 1403 k and 1405 k are consideredangled or inclined with reference to the top (or bottom) edge of theheat conducting plate body 1400 k.

There are two methods for forming the capillary structures 1610 k in theroll-bonded heat exchanger 140 k. In a first method, the capillarystructures 1610 k are placed into the roll-bonded heat exchanger 140 kprior to roll bonding the top and bottom plates of the roll-bonded heatexchanger 140 k. The roll-bonded heat exchanger 140 k may be similar insome aspects to the roll-bonded heat exchanger 140 a and may include twoplates (similar to the plates 1410 a and 1420 a) bonded to each other.In a second method, the capillary structures 1610 k are placed in thechannels 1405 k after roll bonding the two plates forming the heatconducting plate body 1400 k.

In the first method, the capillary structures 1610 k are formed on thesurfaces of plates that form the heat conducting plate body 1400 k by,for example, disposing metal woven mesh on the surfaces of at least oneof the plates facing each other. Specifically, the top and bottom platesof the roll-bonded heat exchanger 140 k are stamped to form the channels1403 k and 1405 k, respectively, and the metal woven mesh is disposed inone of the channels 1403 k and 1405 k. For the sake of discussion, themetal woven mesh is depicted as disposed in channel 1405 k. The metalwoven mesh forms the capillary structure of the heat conducting platebody 1400 k. In one embodiment, the metal woven mesh is welded to thesurface of the plates. Alternatively, the surfaces of the plates arechemically etched to create micro pores or micro structures for formingthe capillary structure of the heat conducting plate body 1400 k. Inanother embodiment, the surfaces of the plates are sandblasted to formthe capillary structure of the heat conducting plate body 1400 k.

Then, the top and bottom plates are contacted against each other and theedges of the plates are sealingly bonded to each other by, for example,a roll bonding process. A blow molding process is then performed tocreate the channels 1405 k. Briefly, in the blow molding process,indentations are provided at predetermined locations on oppositesurfaces of the top and bottom plates. After bonding the two platestogether, gas is pumped into the opening 1406 a. The pressure of the gaswill thus blow up the channels 1405 k along the paths defined by theindentations. The air in the roll-bonded heat exchanger 140 k is removedand the opening 1406 a is sealed by welding, for example.

In the second method, the heat conducting plate body 1400 k is cut alongthe line B shown in FIG. 26, such that, the angled channels 1403 k and1405 k are exposed (See FIG. 27) via openings 1407 k. The capillarystructures 1610 k are respectively placed into the angled channels 1405k via the openings 1407 k along a direction D. FIG. 28 illustrates theheat conducting plate body 1400 k with the capillary structures 1610 kplaced in the angled channels 1405 k. The angled channels 1405 k arereferred to as flow channels since liquid flows through the capillarystructures 1610 k in these channels. The angled channels 1403 k arereferred to as vapor channel since vapor that is generated afterinteraction with a heat generating source flows through these channels.As shown in FIG. 29, a roll bonding process is performed to seal theopenings 1407 k and create a flat structure 150 k. The ends of the flatstructure 150 k are welded to seal the roll-bonded heat exchanger.

The capillary structures 1610 k may be formed in the angled channels1405 k by three different methods. In a first method, copper braids orrolled-up metal meshes or copper cloths are introduced in the angledchannel 1405 k via the openings 1407 k. In a second method (illustratedin FIG. 27), copper powder is sintered to obtain the capillarystructures 1610 k in shape of pillars and the pillars are placed in theinclined channels 1405 k. In the third method, fixtures (e.g.,stick-like structures) are inserted into the angled channels 1405 k andthen copper powder is poured in the space between the angled channels1405 k and the fixtures to fill the space. The roll-bonded heatexchanger 140 k is subjected to vibrations so that the copper powder ismore uniformly filled in the angled channels 1405 k. The copper power issintered to obtain the capillary structures 1610 k.

The roll-bonded heat exchangers according to example embodimentsdiscussed above, provide a guiding structure and a capillary structureto assist coolant to flow opposite to the force of gravity, so that thecoolant in the cooling area located below the heat absorbing area isable to flow back to the heat absorbing area and thereby circulate inthe roll-bonded heat exchanger. Therefore, the heat dissipationefficiency of the roll-bonded heat exchanger is improved. Compared toconventional vapor chambers, the heat dissipation efficiency of thevapor chamber according to example embodiments is increased by at least30 percent.

The foregoing outlines features of several embodiments or examples sothat those skilled in the art may better understand the aspects of thepresent disclosure. Those skilled in the art should appreciate that theymay readily use the present disclosure as a basis for designing ormodifying other processes and structures for carrying out the samepurposes and/or achieving the same advantages of the embodiments orexamples introduced herein. Those skilled in the art should also realizethat such equivalent constructions do not depart from the spirit andscope of the present disclosure, and that they may make various changes,substitutions, and alterations herein without departing from the spiritand scope of the present disclosure.

1. A heat dissipation device, comprising: a first plate having a firstplurality of angled grooves arranged in a first direction; a secondplate having a second plurality of angled grooves arranged in the firstdirection, wherein the second plate is coupled to the first plate, atleast portions of the first plurality of angled grooves and the secondplurality of angled grooves are connected to each other such that thefirst plurality of angled grooves and the second plurality of angledgrooves define a fluid channel of the heat dissipation device, and thefluid channel includes coolant; and at least one capillary structure,wherein at least a portion of the fluid channel is covered by the atleast one capillary structure.
 2. The heat dissipation device accordingto claim 1, wherein the first plurality of angled grooves are not indirect fluid communication with each other, the second plurality ofangled grooves are not in direct fluid communication with each other, aportion of the first plurality of angled grooves and a portion of thesecond plurality of angled grooves intersect each other and the firstplurality of angled grooves are fluidly connected to each other via thesecond plurality of angled grooves.
 3. The heat dissipation deviceaccording to claim 2, wherein the heat dissipation device includes atleast two capillary structures, the at least two capillary structuresare respectively located in at least part of the first plurality ofangled grooves and at least part of the second plurality of angledgrooves.
 4. The heat dissipation device according to claim 1, whereinthe first plate includes a first longitudinal groove extending in thefirst direction, a same end of each groove of the first plurality ofangled grooves is connected to the first longitudinal groove, the secondplate includes a second longitudinal groove extending in the firstdirection, a same end of each groove of the second plurality of angledgrooves is connected to the second longitudinal groove, and the secondlongitudinal groove and the first longitudinal groove are arranged atopposite sides of the first plurality of angled grooves.
 5. The heatdissipation device according to claim 4, wherein the first plurality ofangled grooves are parallel to the second plurality of angled groovesand wherein the first plurality of angled grooves are offset from thesecond plurality of angled grooves.
 6. The heat dissipation deviceaccording to claim 4, wherein the first plurality of angled grooves andthe second plurality of angled grooves intersect each other and thefirst plurality of angled grooves are connected to each other via thesecond plurality of angled grooves.
 7. The heat dissipation deviceaccording to claim 6, wherein the heat dissipation device includes atleast two capillary structures, a first capillary structure of the atleast two capillary structures is arranged in at least a portion of thefirst plurality of angled grooves and the first longitudinal groove, anda second capillary structure of the at least two capillary structures isarranged in at least a portion of the second plurality of angled groovesand the second longitudinal groove.
 8. The heat dissipation deviceaccording to claim 1, wherein the first plate includes two longitudinalgrooves extending in the first direction, opposite ends of each grooveof the first plurality of angled grooves are fluidly connected to thetwo longitudinal grooves of the first plate, the second plate includestwo longitudinal grooves extending in the first direction, opposite endseach groove of the second plurality of angled grooves are connected tothe two longitudinal grooves of the second plate, and the twolongitudinal grooves of the second plate are connected to correspondinglongitudinal grooves of the two longitudinal grooves of the first plate.9. The heat dissipation device according to claim 8, wherein the heatdissipation device includes at least two capillary structures, a firstcapillary structure of the at least two capillary structures is arrangedin at least a portion of the first plurality of angled grooves and thetwo longitudinal grooves of the first plate, and a second capillarystructure of the at least two capillary structures is arranged in atleast a portion of the second plurality of angled grooves and the twolongitudinal grooves of the second plate.
 10. The heat dissipationdevice according to claim 8, wherein the first plurality of angledgrooves are parallel to the second plurality of angled grooves and aredisposed between two adjacent grooves of the second plurality of angledgrooves.
 11. The heat dissipation device according to claim 8, whereinthe first plurality of angled grooves and the second plurality of angledgrooves intersect each other and the first plurality of angled groovesare fluidly connected to each other via the second plurality of angledgrooves.
 12. The heat dissipation device according to claim 1, whereinthe at least one capillary structure is partially submerged in thecoolant.
 13. A heat dissipation device, comprising: a first plateincluding a first plurality of angled grooves arranged in a firstdirection and at least one longitudinal groove extending in the firstdirection, wherein a same end of each groove of the first plurality ofangled grooves is connected to the at least one longitudinal groove; asecond plate coupled to the first plate, wherein the second plate, thefirst plurality of angled grooves and the at least one longitudinalgroove cooperatively form a fluid channel, wherein the fluid channelincludes coolant; and at least one capillary structure, wherein at leasta portion of a surface of the fluid channel is covered by the at leastone capillary structure.
 14. The heat dissipation device according toclaim 13, wherein the at least one capillary structure is located in atleast a portion of the first plurality of angled grooves and the atleast one longitudinal groove.
 15. The heat dissipation device accordingto claim 13, wherein the at least one capillary structure is arranged onthe second plate.
 16. The heat dissipation device according to claim 13,wherein the first plate includes at least two longitudinal grooves,opposite ends of each groove of the first plurality of angled groovesare fluidly connected to the at least two longitudinal grooves.
 17. Theheat dissipation device according to claim 16, wherein the at least onecapillary structure is located in at least a portion of the firstplurality of angled grooves and the at least two longitudinal grooves.18. The heat dissipation device according to claim 16, wherein the atleast one capillary structure is arranged on the second plate.
 19. Theheat dissipation device according to claim 16, wherein the heatdissipation device includes at least two capillary structures, a firstcapillary structure of the at least two capillary structures is arrangedin at least part of the first plurality of angled grooves and the atleast two longitudinal grooves of the first plate, and a secondcapillary structure of the at least two capillary structures is arrangedon the second plate.
 20. The heat dissipation device according to claim13, wherein the at least one capillary structure is partially submergedin the coolant.
 21. A heat dissipating device, comprising: a first plateincluding a first surface; and a second plate sealingly bonded to thefirst plate, the second plate including a second surface contacting thefirst surface, wherein the first plate includes a first recess, thefirst recess at least partially defining a channel of the heatdissipating device, and a first capillary structure is disposed in thechannel and on the first surface.
 22. The heat dissipating device ofclaim 21, further comprising a second capillary structure disposed inthe channel and on the second surface.
 23. The heat dissipating deviceof claim 21, wherein the first capillary structure is disposed on anentirety of the first surface in the channel.
 24. The heat dissipatingdevice of claim 21, wherein the first capillary structure is disposedonly on a portion of the first surface in the channel.
 25. The heatdissipating device of claim 24, wherein the first capillary structure isdisposed in a central portion of the first surface in the channel. 26.The heat dissipating device of claim 21, further comprising a secondcapillary structure disposed in the channel on the first surface andspaced from the first capillary structure.
 27. The heat dissipatingdevice of claim 26, wherein the first capillary structure and the secondcapillary structure are disposed at opposite ends of the first surface.28. The heat dissipating device of claim 21, wherein the second plateincludes a second recess, the second recess at least partially definingthe channel.
 29. The heat dissipating device of claim 28, wherein thefirst recess and the second recess are aligned with each other.
 30. Theheat dissipating device of claim 28, wherein a second capillarystructure is disposed in the channel and on the second surface.
 31. Theheat dissipating device of claim 30, wherein the first capillarystructure is disposed on an entirety of the first surface in thechannel, and the second capillary structure is disposed on an entiretyof the second surface in the channel.
 32. The heat dissipating device ofclaim 28, wherein the first capillary structure is disposed on anentirety of the first surface in the channel.
 33. The heat dissipatingdevice of claim 28, wherein the first capillary structure is disposedonly on a portion of the first surface in the channel.
 34. The heatdissipating device of claim 33, wherein the first capillary structure isdisposed in a central portion of the first surface in the channel. 35.The heat dissipating device of claim 28, further comprising a secondcapillary structure disposed in the channel on the first surface andspaced from the first capillary structure.